Lead singer Caleb Followill unexpectedly walked away from the band’s Dallas show last weekend.

Even more fans were surprised to later discover that the band had cancelled the remaining performances for their 2011 summer tour. Lead singer Caleb Followill cited vocal problems and exhaustion as the culprit, though reports have circulated that more serious issues could be at hand.

Video quickly surfaced on YouTube, documenting Followill’s rambling speech before ultimately exiting the stage. Video also surfaced of the band’s performances from earlier in the evening. In the videos below, Kings of Leon play their tracks “Notion” and “Back Down South.”